Struct TimingMetrics 

pub struct TimingMetrics {
    pub start_time: Instant,
    pub first_byte_time: Option<Instant>,
    pub custom_metrics: Vec<(String, f64, Option<String>)>,
}

Collected timing metrics for a single request.

This struct is stored in request extensions and can be read by interceptors or logging middleware to expose timing data.

Usage

Handlers can access and modify timing metrics via request extensions:

// Add a custom timing metric
if let Some(metrics) = req.get_extension_mut::<TimingMetrics>() {
    metrics.add_metric("db", db_time.as_secs_f64() * 1000.0);
}

Fields

start_time: Instant

When the request processing started.

first_byte_time: Option<Instant>

When the first byte of the response was sent (if known).

custom_metrics: Vec<(String, f64, Option<String>)>

Custom metrics added by handlers (name -> duration_ms).

Implementations

impl TimingMetrics

pub fn new() -> Self

Create new timing metrics starting now.

pub fn with_start_time(start_time: Instant) -> Self

Create timing metrics with a specific start time.

pub fn mark_first_byte(&mut self)

Mark the time when the first byte of the response was sent.

pub fn add_metric(&mut self, name: impl Into<String>, duration_ms: f64)

Add a custom metric (e.g., database query time).

pub fn add_metric_with_desc( &mut self, name: impl Into<String>, duration_ms: f64, desc: impl Into<String>, )

Add a custom metric with a description.

pub fn total_ms(&self) -> f64

Get the total elapsed time in milliseconds.

pub fn ttfb_ms(&self) -> Option<f64>

Get the time-to-first-byte in milliseconds (if available).

pub fn to_server_timing(&self) -> ServerTimingBuilder

Build a Server-Timing header from the collected metrics.

Trait Implementations

impl Clone for TimingMetrics

fn clone(&self) -> TimingMetrics

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TimingMetrics

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for TimingMetrics

fn default() -> Self

Returns the “default value” for a type.